动态将 Rows 值转换为列名并查找总量 - PIVOT

Question

我有 3 张桌子 A、B、C。喜欢

需要显示结合这 3 个表的 sql 表的一些详细信息（结果）。 我需要将日期字段的值动态显示为列标题。 引用此链接http://www.databasejournal.com/features/mssql/converting-rows-to-columns-pivot-and-columns-to-rows-unpivot-in-sql-server.html 但它是针对静态值的。有没有办法为动态数据实现这一点。

提前致谢

Answer 1

这应该可以工作

CREATE TABLE #A (A_ID INT, A_Name Varchar(100))
INSERT INTO #A VALUES (1,'X'),(2,'Y'),(3,'Z');

CREATE TABLE  #B (B_ID INT,A_ID INT, B_Name Varchar(100))
INSERT INTO #B VALUES (10,1,'P'),(11,2,'Q'),(12,1,'R');

CREATE TABLE #C  (B_ID INT,C_DATE DATE, C_QTY INT)
INSERT INTO #C VALUES (10,'2017-01-01',100),(10,'2017-01-02',200),
                       (11,'2017-01-03',250),(11,'2017-01-03',50),(12,'2017-01-07',300);
 ------------- PIVOT AS FOLLOWS                      

DECLARE @Cols AS NVARCHAR(MAX),
        @query  AS NVARCHAR(MAX)
SET @Cols = STUFF((SELECT distinct ',' + QUOTENAME(C_DATE) FROM #C 
    FOR XML PATH(''), TYPE   ).value('.', 'NVARCHAR(MAX)') ,1,1,'')    

SET @query =  'SELECT* FROM(
                SELECT  
                A.A_Name,
                B.B_Name,
                C.C_DATE,
                C.C_QTY
          FROM #A A
          RIGHT JOIN #B B ON A.A_ID=B.A_ID
          RIGHT JOIN #C C ON B.B_ID=C.B_ID
               ) ABC
PIVOT 
(
SUM(C_QTY) FOR [C_DATE] IN (' + @Cols + ')

) AS PV1';

EXEC sp_executesql @query 

DROP TABLE #A; DROP TABLE #B;DROP TABLE #C

Answer 2

相对于 JonWay 之前给出的解决方案，为了添加一个包含 A_name 和 B_name 总量的“结果”列，我们可以创建一个总计视图并将其添加到主查询中

CREATE TABLE A (A_ID INT, A_Name Varchar(100))
INSERT INTO A VALUES (1,'X'),(2,'Y'),(3,'Z');

CREATE TABLE  B (B_ID INT,A_ID INT, B_Name Varchar(100))
INSERT INTO B VALUES (10,1,'P'),(11,2,'Q'),(12,1,'R');

CREATE TABLE C  (B_ID INT,C_DATE DATE, C_QTY INT)
INSERT INTO C VALUES (10,'2017-01-01',100),(10,'2017-01-02',200),
                   (11,'2017-01-03',250),(11,'2017-01-03',50),(12,'2017-01-07',300);

-- Create the view separately after having created the tables
CREATE VIEW R_sum
AS
SELECT A.A_id, B.B_id, SUM(C.C_qty) AS Sum_qty
FROM     A INNER JOIN
                  B ON A.A_id = B.A_id INNER JOIN
                  C ON B.B_id = C.B_id
GROUP BY A.A_id, B.B_id

 ------------- PIVOT AS FOLLOWS                      

DECLARE @Cols AS NVARCHAR(MAX),
        @query  AS NVARCHAR(MAX)
SET @Cols = STUFF((SELECT distinct ',' + QUOTENAME(C_DATE) FROM C 
    FOR XML PATH(''), TYPE   ).value('.', 'NVARCHAR(MAX)') ,1,1,'')    

SET @query =  'SELECT * FROM(
                SELECT  
                A.A_Name,
                B.B_Name,
                C.C_DATE,
                C.C_QTY,
                R.Sum_qty as Result
          FROM A A
          INNER JOIN B ON A.A_ID=B.A_ID
          RIGHT JOIN C ON B.B_ID=C.B_ID
          RIGHT JOIN R_Sum R ON B.A_ID=R.A_ID AND B.B_ID=R.B_ID
               ) ABC
PIVOT 
(
SUM(C_QTY) FOR [C_DATE] IN (' + @Cols + ')

) AS PV1';

EXEC sp_executesql @query